Rotary compressor, blower, and pump.



G. G. CURTIS.

ROTARY COMPRESSOR, BLOWER, AND PUMP.

APPLICATION FILED JUNE 14, 1902. RENEWED MAB. 1, 1907.

1,086,754, Patented Feb. 10, 19M

3 SHEETS-SHEET 1.

, 0. G CURTIS. ROTARY COMPRESSOR, BLOWER, AND PUMP,

APPLIQATION FILED JUNE'l'l, 1902. RENEWED MAR. 1, 1907. 1,086,754. Patented Feb. 10, 19M

3 SHEETS-SHEET 2.

Attorneys- G. G. CURTIS.

ROTARY COMPRESSOR, BLOWER, AND PUMP. APPLICATION rum) JUNE 14, 1902. nnnnwrm mn. 1, 1907.

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UNITED STATES PATENT OFFICE.

CHARLES G. CTIRTIS, OF NEW YORK, N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS, TO

GENERAL ELECTRIC COMPANY, A CORPORATION NEW YORK.

ROTARY COMPRESSOR, BLOWER, AND PUMP.

Specification of Letters Patent.

Patented Feb. 10, 1914...

Appllcationflled June 14, 1902, SeflaI'No. 111,605. Renewed March 1, 1907. Serial No. 360,058.

To all whom it may concern:

Be it known that I, CHARLES G. Qon'rrs, a citizen of the United States, residing in the borough of Manhattan, in the city, county, and State of New York, have mvented a certain new and useful Improvement in Rotary Compressors, Blowers, and- ,speed of rotation, such as would be necessarily employed where the apparatus is coupled directly to an elastic fluid turbine or other high-speed motor. I have found that these results can be accomplished by means of an apparatus which is in effect a reversed elastic fluid turbine.

My present invention is an improvement upon the invention describedin a prior application filed by me (Serial No. 601,606, filed August-4, 1896).

The invention consists in the features of novelty hereinafter pointed out by the claims.

Figure 1 is a radial section through one half of a simple form or element of my apparatus; Fig. 2 is a similar View, illustrating a difierent construction of the 1pressureproducing passage; Figs. 3 and 4: s ow part of the stationary and movable vanes of Figs. 1 and 2 developed in a horizontal plane; Fig. 5 is a view similar to Fig. l, showing movable vanes designed to produce a higher velocity in the fluid, and a discharging passage with vanes of proper angle and shape for convertin this higher velocity into pressure; Fig. 6 s ows a development in a horizontal plane of a set of movable vanes; Fig. 7 is an elevation of one of the vanes of Fig. 6, showing the necessary convergence in the direction of the flow of the fluid to secure a uniform cross-sectional area throughout the length of the vane passages of Fig. 6; Fig. 8 is'a view similar to Fig. 6, showing movable vanes having their tails-set at a forward angle; Fig. 9 is a view similar to Fig. 7 of one of the vanes of Fig. 8; Figs. 10 and 11 are views similar to Figs.- 6 and 7, illustrating the fact that with symmetrically curved and located vanes the top and bottom walls of the vane spaces must be parallel to maintain the cross-sectional area; Fig. 12 is a radial section, through one side, of a form of my apparatus with a number of elements in series and proportioned for the compression of an elast1c fluid; and Fig. 13 1s a development in a horizontal plane of the fluid assages of the apparatus of Fig. 12.

Re erring particularly to Figs. 1 and 3, which illustrate a simple form of the apparatus or an element of a compound apparatus, A is the velocity-producing wheel mounted upon a shaft and driven by any suitable power. Upon its periphery are carried the buckets or vanes a, which have an unsymmetrically curved form. By this I mean that the curved vanes are so disposed upon the wheel as that, either by presenting a sharper angle at the receivlng than at the discharging ends of the vanes or by the shape and proportions of the vane passages,

the pressures will be unbalanced on the opposite sides of the wheel, instead of being balanced, as they would be with symmetrically curved vanes, and consequently the movement of the wheel will draw the fluid in on one side and discharge it on the other with a velocity which is determined by the speed of the wheel and the shape and angles of the vanes. The vanes I employ are provided with sharp or narrow edges at'bot-h their receiving and discharging ends, and this whether the vanes are formed of relatively thin sheet metal bent to the proper curve (as shown in Fig. 8), in which case the ends of the vanes may have the thickness of the metal, or whether such vanes are made thicker at their central sections (Fig. 8), as they will be if out in the peripheries of steel rings a form and method of manufacture which I prefer. The vanes are inclosed by an encircling ring or band 6, which is secured to them. If the angle of the vanes be different on the entering and discharging sides, and the vanes be brought to a sharp edge on each side, the widths of the vane spaces will be greater on one side than on the other. If the top and bottom walls of the vane spaces were made parallel, such spaces would have an increasing crosssectional area in the direction of the flow of the fluid through them. It is important, in order to secure the eifect desired, that there should be no such enlargement of these vane spaces in the direction of flow, and to prevent this I arrange the top and bottom walls of the vane spaces 'so t at they converge toward each other in the direction of flow and thus maintain a substantiall uniform cross-section of the vane spaces t oughout their length, as illustrated in Figs. 6 and 7 and 8 an 9. This is what is required theoretically fereflicient operation. In practical cases, however,ithe formation of eddies by surface ,friction and by centrifu a1 compression may require a slight mo'ification.

cally curved vanes, such as are required in a velocity-producing wheel, a convergence of'the top and bottom walls is necessary to prevent enlargement of the vane spaces.

On the receivin side of the velocityroducing wheel A 5130 the left in Fig. 1 I. provide a stationary delivery chamber B aving a curved form corresponding to the curve of the wheel rim and extending partly or entirely around the circumference of the wheel, according to whether the apparatus isone designed to utilize the entire set of vanes a at the same time or only a part of those vanes. The fluid is drawn from this delivery chamber by the rotation of the wheel. This delivery chamber is constructed with two concentric walls a, d, separated at their inner ends by a space equal to the height of the vane openings on the receiving side of the wheel and approaching as near as practicable to the side of the wheel. These walls a, d, are flared outwardly away from the wheel on curved lines, so as to form a space diminishing in cross-section on curved lines as it approachesthewheel,

' this progressive diminution in cross-sec tional area corresponding with the increasing velocity of the fluid as it approaches the receiving ends of the vanes and conforming in'shape to the contracted vein which the fluid forms in flowing from. a larger to a smaller space. The delivery chamber is divided throughout its width or in that portion adjoining the wheel, by radially placed guide vanes d suflicient in number to re vent the whirling motion 'ven' to the uid by the revolving wheel. l liese guide vanes extend to the inner side of the delivery chamber, so as to'approach as closely as desirable to the receiving ends of-the rotating vanes, any separation at this point greater than is necessary for a proper clearance of parallel withthe axis Lesa-7M the Stationary and rotatinlg parts resulting in a loss in 'eficiency. hey are placed of the velocity-prowheel or'oblique thereto as shown by lines in Fig. 3. The guide vanes of ducin dotte the delivery chamber are also made withsharp or narrow edges at their ends adjoin: ing the rotating vanes, s0 that-the streams of fluid from adjacent sections of the. de-' livery chamber will have only the minimum separation when discharged therefrom 'and will merge into a substantially single stream at the oints of dischar' The ide vanes d'\of t e delivery cham r may 0 made ot thinsheet metal properly secured to, the top and bottom walls of the chamber, in

which case the ed es of the vanes at the dis-1 have the thickness of the' sheetmetal; or such guide vanes may be cast, in one .piece with the top and bottom walls charging ends wil of the delivery chamber and be made thicker at their outer ends and with a diminishing thickness toward their inner ends, Where, they will terminate in sharp edges, the en;

largement of cross-section 1n the direction of flow produced the passages between the site direction.

the spec and form of the vanes. On the discharging side of the moving vanes I provide a pressure-producing passageor chamher 0, which,like-the delivery-chamber on the other side of the Wheel, is made up. of

concentric walls 6, f, extending partly or entirely around the circumference of the Wheel. and flaring outwardly on curved lines away from the wheel, this flare being such that the pressure-producing passage has a gradually increasing cross-sectional area in the directionof the flow of the fluid propor tioned to correspond with the diminishing velocity of the fluid as its ressure gradually increases and its velocity d iacreases, the-curve of enlargement being such as to conform the larger area.. The pressure-producing chamber C ap roaches as closely as practicable the disc ar ing ends of thenloving vanes,and preferfifly is divided .by guide vanes g which are laced at a forward angle obli no to the axis of rotation, so as to stan parallel to the path of the fluid asit leaves the wheel. The guide vanes g are placed radially between t e outer and inner Walls 6, f, and divide the pressure-producing chamber into oblique sections, which correspond with the angle of discharge of. the fluid .from the rotating vanes. The guide by the diverging sides of, idevanes being compensated for by an ad tional separation, of the top and bottom walls d, c, in the oppo;

The fluid is drawn into and traverses the rotating vane spaces and is discharged by 'the movable vanes at a forward angle and fwith a s eed which is dependent both upon in shape to the contracted vein which the fluid forms in passing from the smaller tovanes g extend to the inner end of the chamber C, so as to approach the rotating vanes as closely as practicable; they serve to prevent whirling in the dischargedvfluid and to preserve the direction of flow of the fluid through the pressure-producing chamber, so as to enable the eflicient conversion of velocity into pressure by the gradually enlarging space afforded thereby. These guide vanes 9 may be made of thin sheet metal secured to the outer and inner concentric walls of the pressure-producing chamber, or they may be cast in one piece with such walls, of gradually increasing thickness in the direction of flow, the contraction of the space by the increasing thickness of the guide vanes being compensated for by an additional separation of the inner and outer walls e, f. This gradually enlarging pressure-producing chamber or passage is in principle the nozzle of an elastic fluid turbine reversed in its function so as to convert velocity into pressure, instead of pressure into velocity, as explained in my application Serial No. 601,606 before referred to. As illustrated in Figs. 1 and 3, this reversed nozzle does not decrease in cross-section before reaching the throat h, and is designed to produce only a throat-conversion of velocity into pressure. This is what would be required for the pumping of liquids, andwould also produce sufficient pressure for the blowing of gases or, when the elements are sufiiciently compounded, for the compression of gases.

The pressure-producing chamber C may have a construction similar to the sectional nozzle for elastic fluid turbines described in my Patent No. 700,744, dated May 27, 1902. A construction of this form is illustrated in Figs. 2 and 4. With this form of construction, the pressure-producing passages into which the pressure chamber is divided by the nozzle sections can be given the same cross-sectional area from their receiving ends to the throats of the sections, notwithstanding the increasing thickness of the walls separating the sections, by a change in the form of the cross-sectional perimeter from a rectangular form at the receiving ends of the sections to an elongated curved form at the throats, as illustrated by the projections of the form of these passages at the right of Fig. 4, the upper projection being taken on the line z'i and the lower projection on the line k7c.

If a simple form of apparatus, such as that shown in Figs. 1 and 3 or in Figs. 2 and 4, is used for blowing air or other gases, the delivery chamber B will be open to the air or connected by a conduit of sufficient size to the point from which the air or gases are to be drawn, while the. pressure chamber C will be connected with an outlet passage which will carry off the air or gas at such a rate as to maintain' the pressure in the an air-blower will be stated. The chamber B being open to the air, there will exist in it air at atmospheric pressure or 14.7 lbs. (absolute). The shape 'of the movable buckets a and the speed at which they are driven will be such that a velocity of 1100 feet per second will be produced by these vanes, and the air at this velocity will be projected through the throat h of the pressure-producing chamber, in which this velocity will be converted into pressure and a pressure of 27.9 lbs. (absolute) will be so; cured. The air will be drawn oil from the chamber C at the same rate that it is delivered into the chamber, so that the pressure in the chamber will be maintained.

For securing higher velocities than that which can be efi'ectlvely converted into pressure by the throat action alone, and for con-' verting such velocity into pressure, the construction illustrated in Fig. 5 may be employed for the blowing or compression of elastic fluids. In this figure, due to the fact that the unsymmetrically curved moving vanes terminate with a forward angle. or due to the greater velocity of the vanes or both, the elastic fluid will be delivered to the receiving end of the pressure-producing chamber at a velocity greater than 1100 feet per second, and this makes necessary the contraction of the receiving end of the pressure chamber so as to convert into pressure the velocity in excess of what the throat action alone is capable of converting. In Fig. 5, therefore, the sections into which the pressure chamber is divided have a larger crosssectional area at their receiving ends, as shown by the projection ZZ at the right. of the figure, than at their throats, as shown by the projection mm, and these sections are also set at a sharper angle than are the sections in Figs. 3 and 4, so as to correspond with the sharper angle which the elastic fluid has when discharged at the higher velocity. As an example of the conditions which may exist in a construction such as is shown in Fig. 5, when used for blowing or compressing air, it will be assumed that the atmospheric pressure or 14.7 lbs. (ab solute) exists in the delivery chamber B. Now, if the movable vanes produce a velocity of 1630 feetper second, the area of the receiving ends l-Z of the sections of the pressure chamber must be 1.143, as compared with an area of 1.0 for the throats m-m of these sections. These being the conditions of the apparatus, the air will be received by the sections of the pressure chamber at a velocity of 1630 feet per sec- 0nd and with atmospheric pressure, and in and from that the pressure will be increased to 26.5 lbs.

(absolute), when the throat will be reached. oint to the lar est section of the ressure c amber the v ocity' will be gra ually decreased and the pressure increased until the former reaches zero and 1 (gabsolute the latter attains the maximum of 50 lbs. The air will, of course, be

rawn o from the pressure chamber C at such a rate as'to maintain this pressure therein. This form of a? aratus is not suit ableforthe pumping o liquids, on account -1 of their incompressibllity, but isa'da ted for the compression of elastic fluids. T ese are the theoretical figures. In practice the losses from friction and eddy currents Wlll moilifv these pressures, reducing them more ess.

In Figs. 12 and 13, there isillustrated a compound apparatus produced by arranging in succession three elements such as that shown in Figs. 1 and 3 and usin only .part of the circumference of the ve ocityproducing wheels. A, A, A are the three velocity-producing wheels, mounted upon the same shaft and rotating to ether, and having vanes a the same as t e element shown in Fig. 1. The inclosing shell is provided with heads D, D, preferably semicircular, so as. to divide at the shaft. The

cylindrical portion of the shell is made up a channel-iron of parts E, E, E havin cross-section, each section eing preferably made in two parts. Between the sections E, "E', E are diaphragm or partition plates F, F, which are held between the flanges of the sections E, E, E. In the head D is located the delivery chamber B having guide vanes d. Supported in the artition F is the pressure chamber 0 having the guide vanes 9, receiving at its throat h the fluid delivered by the first wheel A and delivering this fluid to the vanes ofthe second wheel A by an openin h which is sulficiently smaller. than t e opening at the small end of the delivery chamber B to convey the same volume of elastic fluid at the higher pressure. A smaller pressure chamher 0 is supported. by the partition F be tween the wheels A and A, while another such chamber 0* is supported by the head D and receives the fluid from the final wheel A. The height of the vanes a is less in the successive wheels, and the receiving and discharging ends of the pressure .chambers may also be made progressively of smaller area, so as to compensate for the decreased volume ofthe elastic fluid due to its increased pressure. If, however, the appaweaves cross-section. Where the fluid passageway art of the circumference of the wheels, as illustrated in Figs. 12gand 13, covering rings G are employed,;which cover both ends of the moving vane spaces,

occupies only a except where they are in line with the fluid passage through the delivery and pressure chambers. The purpose of ithes'e covering plates is to prevent circulation of the an in the 'wheel chambers into which the shell is divided. In these wheel chambers, difier ent pressures will, of course, be maintained, corresponding with the pressures at the clearances, and in order to prevent a waste of power it is desirable, where the delivery and pressure chambers occupy only a portion of the circumference, that the moving vanes should not waste power 1n circulating the air in these wheel chambers.

The successive pressure chambers C, Q, 0*, are set progressively farther ahead 1n the direction of rotation (71. e., are given the proper lead as shown in Flg. 13, to compensate for the forward movement which the column or jet of air is given by the moving vanes.

The conditions of operation of such. an apparatus as is illustrated in Figs. 12 and 13, when used for the blowing or compresing of air, may be as follows :If each of the velocity-producing wheels produces avelocity of 1100 feet per second, the pres sures at B, C, C and C will be respectively,

in lbs. absolute, 141,219, 53 and 10.0, it

being understood that the air will be drawn off from the final pressure chamber C at such a rate as to maintain the last-named pressure in that chamber. If the compound apparatus of Figs. 12 and 13 was rovided with a series of elements such as is shown in Fig. 5, in which a higher velocity than 1100 feet per second was produced, and the pressure chambers were'constructed in proportion to convert this velocity into pressure, a higher final pressure would be secured. Assuming the conditions already assumed for illustration in connection with Fig. 5, the three-stage apparatus would have its wheels each capable of producing a velocity of 1630 feet per second, and the pressure developed at the first stage would be 50 lbs., and at each succeeding stage an increase of pressure would be produced equivalent to the velocity of 1630 feet per second.

The function of the passage into which the impeller discharges is that of a reversed nozzle. In the type of apparatus, in which the passage expands immediately from the entrance or throat, or expands .without preliminarily contracting to the throat,-such being in fact a reversed non-expansion nozzle -there will be a throat conversion only.

with a straight sided nozzle, the maximum conversion of pressure, in the case of steam, corresponds with 57.7% of the initial pressure. It is pointed out in the Laval patent, if the nozzles are diverged at the proper angle between the throat or narrowest part of the nozzle and its discharge end there is a further conversion of pressure into velocity. In the steam turbine art, a straight sided nozzle, or one in which there is no enlargement of the cross-sectional area beyond the throat, is referred to as a nozzle producing a throat conversion. In the reversal of the nozzle and its utilization for convert ing velocity into pressure, where there is no diminution of cross-sectional area between the receiving end and the throat, there is produced only a throat conversion of velocity into pressure; whereas, if there is such a diminution in cross-sectional area, a greater conversion is produced. The specific illustrations given in this specification show the eflect of the reversal of these two kinds of nozzle. With air, the throat pressure is approximately 52.68% instead of.57.7%, as

is the case with steam. I have disclosed my invention in connection with an apparatus of the axial flow type, i. e., in which the path of the fluid is parallel to the axis of the impeller; but I desire it to be understood that my invention is not to be limited to such type of apparatus'as it may be embodied in apparatus of difi'erent type.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is as follows 1. In a rotary fluid-pressure-producing apparatus, the combination with a velocityproducingwheel, of a pressure producing passage, receiving the fluid from the wheel and converting velocity into pressure, such pressure producing passage flaring outward away from the wheel, the flare being such that the passage has a gradually increasing cross sectional area in the direction of flow of the fluid proportioned to correspond with the diminishing velocity of the fluid as its pressure gradually increases and its velocity decreases, and being divided by vanes which extend to the inner end of the passage, and maintain the direction of flow of the fluid during the conversion of velocity into pressure, substantially as set forth.

2. In a rotary fluid-pressure producingapparatus, the combination with a velocityproducing Wheel, of a pressure producing passage, receiving the fluid from the wheel and converting velocity into pressure, such pressure producing passage flaring outward away from the wheel, the flare being such that the passage has a gradually increasing cross sectional area in the direction of flow of the fluid proportioned to correspond with the diminishing velocity of the fluid as its pressure gradually increases and its velocity decreases, and being divided by vanes set at a forward angle approximately parallel with the direction of flow of the fluid discharged by the wheel, the said vanes extending to the inner end of the passage, substantially as set forth.

3. In a rotary fluid-pressure-producing apparatus adapted to produce a throat-conversion of velocity into pressure, the combination with a velocity-producing wheel, of a pressure producing passage connected with the vane passages of such wheel without dimlnution of cross-sectional area in the connecting passageway, such pressure producing passage flaring outward away from the wheel, the flare being such that the passage has a gradually increasing cross sectional area in the direction of flow of the fluid proportioned to correspond with the diminishing velocity of the fluid as its pressure gradually increases and its velocity decreases, substantially as set forth.

4. In a rotary fluid-pressure-producing apparatus adapted to produce a throat-conversion of velocity into pressure, the combination with a velocity-producing wheel, of a pressure producing passage connected with the vane passages of such Wheel without diminution of cross-sectional area in the connecting passageway, such pressure producing passage flaring outward away from the wheel, the flare being such that the passage has a gradually increasing cross sectional area in the direction of flow of the fluid proportioned to correspond with the diminishing velocity of the fluid as its pressure gradually increases and its velocity decreases, and being divided by vanes which extend to the inner end of the passage, and maintain'the direction of flow of the fluid during the conversion of velocity into pressure, substantially as set forth.

5. In a rotary fluid pressure producing apparatus adapted to produce a throat-conversion of velocity into pressure, the combination with a velocity-producing wheel, of a pressure producing passage connected with the vane passages of such wheel without diminution of cross-sectional area in the connecting passage-way, such pressure producing passage flaring outward away from the wheel, the flare being such that the passage has a gradually increasing cross sectional area in the direction of flow of the fluid proportioned to correspond with the diminishing velocity of the fluid as its pressure gradually increases and its velocity decreases, and being divided by vanes set at a forward angle approximately parallel with the direction of flow of the fluid discharged by the wheel, the said vanes extending to the inner end of the passage, substantially as set forth 6. In a rotary fluidpressure producing apparatus, the combination with a velocityside' of t e wheel 1 apparatus, the combination with a velocity roducing wheel,of a delivery chamber on the inlet side of the wheel having a gradually diminishing cross sectional area, and a pressure producing passage on the outlet side of t e wheel, flaring outward away from the Wheel, the flare being such that the passage has a gradually increasing cross sectional area in the direction of flow of the fluid proportioned to correspond with the dimimshing'velocity of the fluid as its pres sure gradually increases and its velocity"de-. creases, such-delivery and pressure cham bers being divided by vanes or which extend to the inner end 0 the passage, substantially as set forth. 8.: In a rotary fluid pressure producing V apparatus, the combination with a velocity producing wheel carrying unsymmetrically curved vanes having a decreasing depth in the direction of flow, of a delivery chamber and a pressure reducing passage located respectively on't e inlet and outlet sides of said wheels, such chamber and passage having respectively a gradually decreasing and a gradually increasing cross sectional area in the direction of flow of the fluid, the said pressure producin passage flaring outward away from the w eel, the flare being such that the assage has a adually increasing cross sectional area in t c direction of'flow of the fluid proportioned to correspond with the diminishing velocity of the fluid as its pressure gradually increases and its velocity decreases, substantially as set forth.

9. In a rotary fluid pressure producing apparatus, the combination with a velocity producing wheel carrying unsymmetrically curved vanes having a decreasing depth in.

the direction of flow, of a delivery chamber and a pressure producing. passage located respectively on the inlet and outlet sides of sai wheels, lsuch chamber and passagehaving respectively agradually decreasing and a gradually increasing cross sectional-area inthe'direction of flow of the fluid, the said pressure producin passage flaring outward away :from the w eel, the flare being such that the passagehas a gradually increasing cross sectlonal area in the directionof flow of the fluid proportioned to correspond with the diminishing velocity of-the fluid as its artitions tenet pressure gradually increases and its velocity decreases, and being divided by vanes or partitions which extend to the. inner end of the passage, substantially as set forth. 10. In a rotary fluid pressure producing apparatus, the combination with two or more velocity producing wheels connected in succession, of a pressure passage between each wheel and the next in succession, the said passage flaring outward away from the wheel, the flare being such that the passage has a gradually increasing cross sectional area in the direction of How of the fluid proportioned to corres 0nd with the diminishing velocity of the fluld as its pressure gradually increases and its velocity decreases, such pressure passage being divided by vanes or partitions at its receiving and discharging ends, substantially as set forth.

11. In a rotary fluid pressure producing apparatus, the combination with two or more velocity producing wheels-connected in succession, of a delivery passage on the inlet side of the first wheel having a gradually deand the next in succession, the said passage flaring) outwardaway from the wheel, the flare eing such that the passage has it gradually increasing cross sectional area in the direction'of flow of the fluid proportioned to correspond with the diminishing velocity of the fluid as its pressure gradually increases and its velocity decreases, substantially as set forth.

12. In a rotary fluid pressure producing apparatus, the combination with two or more velocity producing wheels connected in succession, of a delivery passage on the inlet side of the first wheel having a gradually de creasing cross section in the direction of flow, and a pressure passage between each wheel and the next in succession, the said passage flaring outward away from the wheel, the flare being such that the passage has a gradually increasing cross sectional area in the direction of flow of the fluid proportioned to correspond with'the diminishing velocity of the fluid as its pressure gradually increases and its velocity decreases, suchpassages being divided by vanes or partitions, substantially as set forth.

13. In a rotary fluid. pressure producing apparatus,jadapted to produce pressure by a succession of throat conversions of velocity into pressure,- the combination with two or more velocity roducing wheels connected in succession, o a pressure chamber followingeach wheel'and receiving the fluid there'- from, such chamber being connected with the wheel without diminution of cross sectional area in the connecting passageway and fiarmg outward away from the wheel, the flare hemg such that the passage has agradually increasing cross sectional area in the direction of flow of the fluid proportioned to correspond with the diminishin velocity of the fluid as its pressure gradual y increases and without diminution of cross sectional area in the connecting passageway and flaring outward away from the wheel, the flare being such that the passage has a gradually increasing cross sectional area in the direction of flow of the fluid pro rtioned to corres 0nd with the diminishing velocity of the uid as its pressure gradually increases and its velocity decreases, and vanes or partitions in the gradually enlarging ressure chamber to maintain the direction 0 flow of the fluid during the conversion of velocity into pressure, the said vanes extending to the inner gndhof the chamber, substantially .as set ort 15. In a rotary fluid pressure producing apparatus, the combination with two or more such chambers being set progressivel for ward in the direction of rotation, su stantlally as set forth.

16. In a rotary fluid pressure producing.

apparatus, the combination with two or more velocity roducing wheels connected in succession, o a delivery chamber and two or'more pressure chambers occupying a part only .of the circumference of the wheels, such chambers being set progressively forward in the direction of rotation and divided by vanes or partitions, substantially asset forth.

17. In a compressor for elastic fluids, the combination with a rotalg impeller by which velocity is imparted to t which has walls diverging in the direction of flow and has such position and dimensions that it will guide the fluid in its passage from the impeller in substantially the direction of the movement imparted to it by the impeller, the rate of divergence of its walls being so proportioned to the movement and elasticity of the fluid that a considerable portion or all of the velocity of the fluid will be converted into pressure during its passage through the nozzle.

This specification signed and witnessed this 10th day of June, 1902.

CHARLES G. cunrrs.

Witnesses:

J N0. Ronr TAYLOR, J OHN LOUIS Lo'rscn.

e fluid, of a nozzle adapted to receive fluid from the impeller 

